"pertaining to slugs," 1650s, with -ous + Latin limax (genitive limacis) "snail, slug," from Greek leimax, from PIE root *(s)lei- "slime" (see slime (n.)). The Greek word is cognate with Russian slimák "snail," Lithuanian sliekas "earthworm," and the first element in Old English slaw-wyrm "slow-worm."
"destroy, eradicate," 1530s, from Latin deletus, past participle of delere "destroy, blot out, efface," from delevi, originally perfective tense of delinere "to daub, erase by smudging" (as of the wax on a writing table), from de "from, away" (see de-) + linere "to smear, wipe," from PIE root *(s)lei- "slime, slimy, sticky" (see slime (n.)). In English, specifically in reference to written matter from c. 1600. Related: Deleted; deleting.
The noun meaning "part of a country lying along the coast" is from 1828, from Italian littorale, originally an adjective, from Latin littoralis. Compare Lido.